The instant invention relates to reinforcement for an expandable composition. The instant invention also relates to a method of using the reinforcement to retain an expandable composition, for example, within an automotive cavity.
Expandable sealants are known in this art such as described in U.S. Pat. Nos. 4,427,481; 4,874,650; 5,106,415; 5,266,133; 5,373,027; 5,506,025; 5,266,133; 5,373,027; and 5,678,826; and European Patent No. EP 0 730 998B1; the disclosure of each of which is hereby incorporated by reference. One conventional cavity sealing arrangement and method is described in U.S. Pat. No. 5,040,803; the disclosure of which is also hereby incorporated by reference. Other convention cavity sealants comprise polyvinyl chloride (PVC), and polyurethane (PU) based materials that are pumped into location and, in some cases, expand after being exposed to a sufficient amount of heat. Conventional sealants also include epoxy containing foams, and combining PU and epoxy foaming systems.
In some cases, the expandable sealant is preformed to have a defined configuration. The preformed sealant can be located within a cavity or an area for sealing and then heated. The heating (e.g., that is used to bake automotive paints), causes the sealant to expand and in turn form a seal. Preformed automotive sealants are available from Orbseal LLC, Richmond, Miss. as Product Numbers 136, 157, 20000, 20100, 21000, 21100, among others. Typically, these sealants are employed in automotive applications for filing cavities, stiffening adjacent components and dampening sound/vibrations. Such sealants are employed to satisfy automotive specifications such as Ford Specification WSS M99P35-A, WSS M99P29-A and WSSM2D494-A; the disclosure of which is incorporated by reference.
Conventional foam compositions are described in U.S. Pat. Nos. 6,058,673; 5,574,124; 4,052,347; 4,355,138; 5,461,091; 4,963,675; 5,356,943; 5,350,777; 4,910,332; 5,817,860; 4,888,442; 4,855,490; 4,864,025; 4,904,522 and 5,461,091, and WIPO Publication Nos. WO 96/06124 and WO 98/52997. Polyurethane foam compositions and compositions having reduced MDI content are described in U.S. Pat. Nos. 5,817,860; 5,574,124; 4,052,347; 4,355,138; 4,888,442; 4,864,025; 4,855,490; 4,963,675; 5,350,777; 4,910,332; 5,356,943, European Patent Application Publication No. 0 393 903 A2 and WIPO Publication No. WO/96/06124. The disclosure of these patents and patent application publications is incorporated by reference.
Expandable and foaming compositions can extend beyond the intended area to be sealed (e.g., foaming compositions are dispensed into a cavity as a stream/froth that may flow into undesired areas). There is a need in this art for an expandable composition that: 1) is reinforced to improve strength and control material flow during expansion, 2) can be adhered or affixed to a metal substrate, 3) is easily installed and remains in a predetermined location, and 4) for some applications provides acoustical or structural properties to the surrounding members, e.g., an automotive cavity.
The instant invention solves problems associated with conventional expandable materials and foams, and application methods by providing a reinforcement that contacts the expandable material/foam during expansion. In contrast to conventional materials and methods, the instant invention can: 1) provide reinforcement to an expandable material having a predetermined or preformed shape, e.g., extrusion, stamping, and injection molding, 2) be located, e.g., within a cavity, or around or upon a member to be sealed, prior to/post assembly while remaining in a predetermined location, 3) be employed in a wide range of applications, 4) control flow rate and direction of foaming compositions; and 5) provide increased strength/reinforcement after expansion/foaming. By employing at least one of the inventive reinforcement, at least a portion or substantially all of a predetermined cavity can be filled. When employed in an automotive cavity, the inventive reinforcement permits selective placement of an expandable composition thereby avoiding excessive material usage (and attendant weight gain) and providing improved acoustical/structural properties to adjacent metallic components. If desired, the inventive reinforcement permits a predetermined amount of an expandable material to be located within an automotive cavity for structural reinforcement thereby permitting a reduced gauge of metal to be used without reducing the strength of the cavity or increasing overall weight.
The inventive reinforcement comprises a first and a second member each having protuberances that are contacted when the first and second members are joined. The members are joined by bending a hinge that separates the members, or can be joined in multiple units to form a series. The members are maintained in a closed or joined position by at least one latch. Once joined, the first and second members define at least one opening wherein a foaming composition can be injected into the joined members. Alternatively, a preformed expandable material can be placed between the first and second members, or located on selected outer positions, e.g., within an automotive cavity to be sealed. By selecting the location and number of reinforcement members, all or a portion of a cavity can be filled with an expandable composition. In either case, the foaming/expanding material embeds the reinforcement. The foam/expandable material can expand further as the material cures as well as a result of subsequent processing, e.g., during the automotive assembly process.